title: Magnetic ordering and charge dynamics in κ-(BEDT-TTF)2Cu[N(CN)2]Cl.
abstract: The Mott insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl consists of molecular dimers arranged on an anisotropic triangular lattice. At low temperatures a pronounced dielectric anomaly is observed, and eventually a canted antiferromagnetic ground state forms. Optical spectroscopy clearly rules out charge imbalance and the existence of quantum electric dipoles with a dipolar-spin coupling. Here we suggest a novel form of spin-charge coupling where the prominent in-plane dielectric response in κ-(BEDT-TTF)2Cu[N(CN)2]Cl is explained by short-range discommensurations of the antiferromagnetic phase in the temperature range 30 K < T < 50 K, and by relaxation of charged domain walls in the ferromagnetic structure at lower temperatures.
authors.affiliation: Institut za fiziku, PO Box 304, HR-10001 Zagreb, Croatia.
authors.forename: S
authors.initials: S
authors.lastname: Tomić
authors.forename: M
authors.initials: M
authors.lastname: Pinterić
authors.forename: T
authors.initials: T
authors.lastname: Ivek
authors.forename: K
authors.initials: K
authors.lastname: Sedlmeier
authors.forename: R
authors.initials: R
authors.lastname: Beyer
authors.forename: D
authors.initials: D
authors.lastname: Wu
authors.forename: J A
authors.initials: JA
authors.lastname: Schlueter
authors.forename: D
authors.initials: D
authors.lastname: Schweitzer
authors.forename: M
authors.initials: M
authors.lastname: Dressel